diff --git a/bash_profile b/bash_profile
index b43a312..2c340e9 100644
--- a/bash_profile
+++ b/bash_profile
@@ -9,11 +9,11 @@ fi
 # sudo usermod -a -G wheel ljh
 # sudo -E env "PATH=$PATH" swift main.swift
 
-EDITOR=$(which vi)  # update-alternative --config EDITOR
 alias ls="ls --color=never"
 alias tree="tree -n"
+EDITOR=$(which vi)  # update-alternative --config EDITOR
 
 export HISTCONTROL="ignoredups:erasedups:ignorespace"
 export PROMPT_COMMAND='history -a'
-export PATH=$PATH:../boost_1_73_0/stage/lib
 export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:../boost_1_73_0/stage/lib
+export PATH=$PATH:../boost_1_73_0/stage/lib
diff --git a/bashrc b/bashrc
index c371ab9..b1b1e70 100644
--- a/bashrc
+++ b/bashrc
@@ -2,9 +2,14 @@
 ## put environment variables like PATH in ~/.profile
 
 alias ls="ls --color=never"
+alias tree="tree -n"
 EDITOR=/usr/bin/vi
-export HISTCONTROL="ignoredups:erasedups"
+
+export HISTCONTROL="ignoredups:erasedups:ignorespace"
 export PROMPT_COMMAND='history -a'
+export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:../boost_1_73_0/stage/lib
+export PATH=$PATH:../boost_1_73_0/stage/lib
+
 PS1='\$ '
 set -o vi  # set editing-mode vi # ~/.inputrc,
 stty -ixon  # terminal flow control Ctrl-S conflicts with vim, emacs.
diff --git a/debian_install.txt b/debian_install.txt
index e763082..9ca18c6 100644
--- a/debian_install.txt
+++ b/debian_install.txt
@@ -121,9 +121,14 @@ $
 # environment variables in ~/.profile, eg. PATH
 $ vi ~/.bashrc
 alias ls="ls --color=never"
-EDITOR=/usr/bin/vim
-export HISTCONTROL="ignoredups:erasedups"
+alias tree="tree -n"
+EDITOR=/usr/bin/vi
+
+export HISTCONTROL="ignoredups:erasedups:ignorespace"
 export PROMPT_COMMAND='history -a'
+export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:../boost_1_73_0/stage/lib
+export PATH=$PATH:../boost_1_73_0/stage/lib
+
 PS1='\$ '
 set -o vi  # set editing-mode vi # ~/.inputrc,
 stty -ixon  # terminal flow control Ctrl-S conflicts with vim, emacs.
diff --git a/fedora_install.txt b/fedora_install.txt
index 4bf1ff7..f37c6e0 100644
--- a/fedora_install.txt
+++ b/fedora_install.txt
@@ -106,9 +106,14 @@ $
 
 $ vi ~/.bashrc
 alias ls="ls --color=never"
-EDITOR=/usr/bin/vim
-export HISTCONTROL="ignoredups:erasedups"
+alias tree="tree -n"
+EDITOR=/usr/bin/vi
+
+export HISTCONTROL="ignoredups:erasedups:ignorespace"
 export PROMPT_COMMAND='history -a'
+export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:../boost_1_73_0/stage/lib
+export PATH=$PATH:../boost_1_73_0/stage/lib
+
 PS1='\$ '
 set -o vi  # set editing-mode vi # ~/.inputrc,
 stty -ixon  # terminal flow control Ctrl-S conflicts with vim, emacs.
diff --git a/profile b/profile
index 969e303..a4d548f 100644
--- a/profile
+++ b/profile
@@ -1,14 +1,16 @@
 # ~/.profile
+## put environment variables like PATH in ~/.profile
 
-PS1='\$ '
-set -o vi
-ulimit -c unlimited
-
-EDITOR=$(which vi)  # update-alternative --config EDITOR
 alias ls="ls --color=never"
 alias tree="tree -n"
+EDITOR=/usr/bin/vi
 
 export HISTCONTROL="ignoredups:erasedups:ignorespace"
 export PROMPT_COMMAND='history -a'
-export PATH=$PATH:../boost_1_73_0/stage/lib
 export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:../boost_1_73_0/stage/lib
+export PATH=$PATH:../boost_1_73_0/stage/lib
+
+PS1='\$ '
+set -o vi  # set editing-mode vi # ~/.inputrc,
+stty -ixon  # terminal flow control Ctrl-S conflicts with vim, emacs.
+ulimit -c unlimited  # systemd-coredump
diff --git a/ubuntu_install.txt b/ubuntu_install.txt
index 031a294..1a1cbd5 100644
--- a/ubuntu_install.txt
+++ b/ubuntu_install.txt
@@ -152,9 +152,14 @@ $
 ## environment variables in ~/.profile, eg. PATH
 $ vi ~/.bashrc
 alias ls="ls --color=never"
-EDITOR=/usr/bin/vim
-export HISTCONTROL="ignoredups:erasedups"
+alias tree="tree -n"
+EDITOR=/usr/bin/vi
+
+export HISTCONTROL="ignoredups:erasedups:ignorespace"
 export PROMPT_COMMAND='history -a'
+export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:../boost_1_73_0/stage/lib
+export PATH=$PATH:../boost_1_73_0/stage/lib
+
 PS1='\$ '
 set -o vi  # set editing-mode vi # ~/.inputrc,
 stty -ixon  # terminal flow control Ctrl-S conflicts with vim, emacs.
diff --git a/zshrc b/zshrc
index 0d5c872..0b2c85e 100644
--- a/zshrc
+++ b/zshrc
@@ -1,9 +1,13 @@
 # ~/.zshrc
 # macOS
 
-PS1='$ '
-set -k
-
 # vi mode
 # TAB for filename completion
 bindkey -v
+
+PS1='$ '
+set -k
+set -o vi
+
+stty -ixon
+ulimit -c unlimited